1. Field of the Invention
The present invention relates generally to a locating device for locating missing persons, crafts and other objects in search and rescue operations. More particularly, the present invention relates to an inflatable emergency passive radar locating device which is compact, lightweight and easily adapted for use in an emergency where individuals, crafts and other objects are lost at land or at sea.
2. Description of the Prior Art
There is a need to enhance the ability for search and rescue personnel to locate missing person and craft, such as boats, land vehicles and aircraft. Missing persons, which search and rescue missions attempt to locate, include aviators, hikers, boaters, skiers and other civilian and military personnel lost in remote areas.
Active electronic devices are available such as transponders and GPS systems to assist search and rescue personnel in locating missing persons and craft. However, active electronic devices are generally very expensive and require maintenance to insure that the device is operational.
Passive locating devices are also available to assist search and rescue personnel in locating missing persons and craft. One such device is disclosed in U.S. Pat. No. 4,901,081, entitled "Elliptical Inflatable Radar Reflector" to John H. Bain, Jr. et al. The radar reflector of U.S. Pat. No. 4,901,081, which has use in search and rescue operations includes a collapsible and inflatable radar wave permeable envelope which when inflated assumes the shape of an ellipsoid. The ellipsoid envelope surrounds a radar reflective array having a number of radar wave reflectors which, when the envelope is inflated, are arranged to form a plurality of corner reflectors. The reflectors are in the shape of right multilaterals having two sides perpendicular to one another and the other sides forming obtuse angles where the apexes of these angles may provide points of attachment to the inner surface of the inflatable envelope.
While these passive locating devices are generally satisfactory for their intended purpose of locating missing persons and craft, there are deficiencies inherent in these passive locating devices which limit their use in search and rescue operations. The complexity and/or bulk (assembled or unassembled) of passive locating devices do not limit themselves to low cost, compact, lightweight applications such as use by skiers and hikers.
In addition, many passive locating devices incorporate a deployment system which fills a balloon with lighter than air gas. The balloon when fully inflated carries a radar reflector above the land or sea surface enhancing the ability of search and rescue personnel to locate missing persons or craft. These passive locating devices are often very complex, bulky and very expensive.
Other passive locating devices include foam filled inflatables which float on the water's surface, but are still complex, bulky and generally expensive.
Accordingly, there is a need for passive locating device which is relatively compact, lightweight, low cost and disposable and which may function as the primary locating device or a backup locating device.